When arid regions are to be used for agricultural use or plant husbandry, or are to be cultivated in some manner, such as when planting sod for a golf course, the viability of such a project is contingent upon the delicate balance that must be struck between the harvest and/or the fees which can be charged for the agricultural operation coupled with the expenses required to maintain the area in a non-arid state.
Even in non-arid regions, periodic droughts can cause a growing enterprise to be curbed because of a temporary unavailability of water. Moreover, an increased cost in making water available can make projects which were once feasible no longer feasible.
Polymers are known to exist, which, when mixed in soil or other growing media can extend the time between watering. One such known polymer is formed as a cross-linked potassium polyacrylate/polyacrylamide copolymer marketed by Stockhousen in Greensboro, N.C. under the name STOCKOSORB.RTM.. Apparently, the polymer acts as a hydrophylic trap and retains the moisture in a strategic location immediately adjacent the root zone of the plants to be grown and keeps the water at that level for subsequent incremental extraction by the plant as needed. In many watering operations involving soil having the less than optimal friability, a majority of the water is lost by run off or migration away from the root zone of the crops or plants to be grown. Thus, in order for polymers to exhibit the maximum effectiveness, it is essential that they be uniformly placed at an appropriate distance with respect to the root zone of the plants being grown.
One known technique for dispensing the polymer involves mixing the polymer with water in an injection pump which directly receives the polymer. Water is then pumped therein at high pressure. Please see FIG. 13. Mixing polymer in this manner stresses the equipment because the polymer may clump up when mixed in this fashion, especially when dispensing is to be throttled on and off.
It is also known in the prior art to provide an apparatus which attempts to administer the polymer in a liquid solution as a uniform continuous stream into the ground. The problem with attempting to provide such a stream of material in a liquid form and causing it to enter into the ground is that such high pressure is involved that the mechanical appliances associated with the distribution of the liquid and polymer make the system unreliable and prone to failure because it cannot simultaneously and continuously achieve the force required to accurately penetrate the soil in a small, safe to use machine.
In the past, it is known to treat sod on golf courses with this polymer by slicing into the sod using a disc-like implement or injecting a liquid ribbon. When placing the polymer in a furrow by the disc, one then must roll down the soil atop the thus placed polymer. One problem with either technique involves the spacing between adjacent discs or ribbons. This provides a limitation controlling the distance between rows of polymer. The effect of providing a linear ribbon of polymer is that the sod manipulated in this way swells in a non-uniform manner in the presence of moisture. The result is to form "washer-board" undulations on the surface of the golf course because of the tendency of the polymer to swell. This provides non-uniform expansion between the polymer treated area versus the non-polymerized portions of the sod when irrigating. This varied surface has no place on a facility such as a golf course where washer board undulations are an anathema to the game of golf.
Other machinery to facilitate the injection of fluids, as well as methods for such injection have been provided. However, none of the prior art devices contemplate the desirability of using a machine in combination with an additive in a liquid which decreases the need for subsequent irrigation. The focal point of the prior art devices has been to provide conditioning to soil which facilitates the growth of plants, rather than reducing the need for subsequent irrigation. It should be noted however that the present invention is not limited to only injecting a polymer mixture, and as configured is capable of injecting other substances, such as fertilizers, pesticides and herbicides into the soil as needed.
The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicants' acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
______________________________________ INVENTOR PATENT NO. ISSUE DATE ______________________________________ Marron, et al. 2,930,334 March 29, 1960 Baldwin, et al. 3,012,526 December 12, 1961 Johnston 3,521,819 July 28, 1970 Kainson, et al. 3,815,525 June 11, 1974 Pustovoit, et al. 3,875,876 April 8, 1975 Russell, et al. 4,009,666 March 1, 1977 Koslow, et al. 4,163,657 August 7, 1979 Jinno, et al. 4,164,413 August 14, 1979 Koslow, et al. 4,380,886 April 26, 1983 Youssef, et al. 4,927,447 May 22, 1990 Tanaka 5,013,349 May 7, 1991 ______________________________________
The patent to Baldwin, et al. teaches the use of a supply tank 39 filled with agricultural chemicals in liquid form which is delivered to a calibration tank 30 by means of a transfer pump 38. When the tank 30 is full, valves 41 and 44 are shut off and a vent valve 45 is open to permit gravity flow from tank 30 into a line 31. A clutch 88, when engaged, powers a high pressure pump 15 from rear wheels 12 of a tractor, causing liquid to be drawn from the tank 30 through a check valve 32 and delivered under high pressure through a line 35. Line 35 conveys the liquid to a delivery valve 36 mounted on a frame 70. In this manner a series of liquid "slugs" are propelled at high pressure through an outlet 57 into the soil.
Similarly, the patent to Marron, et al. teaches the use of a soil treatment apparatus in which a vehicle is provided with a power unit 15, a shaft 16 driven by the power unit, a belt 24 which, through shaft 16, drives a second shaft 27 upon which a cam 30 is provided. The cam 30 actuates the fluid injecting mechanisms during each revolution of the shaft 27. More specifically, a plurality of injector units 32 are arranged side by side in a row and the cam 30 is provided with a spirally shaped rise to operate the injector units. A storage tank 34 delivers the liquid through a hose 35 and a filtering unit 36 and is fed to a distributing manifold 37 to the injector units. Notice a check valve including a housing 40, valve number 41 and valve spring 42 (FIG. 3) to permit the flow of liquid into the port 39 of injector unit 32 and to prevent back flow.
The patent to Koslow, et al. teaches the use of a soil conditioning composition which is to be mixed with soil. In general, a polymer is delivered into the soil as a method for retarding the loss of water from the water permeable soil. Initially the polymer contacts the soil thereby conditioning the soil. After irrigating the soil at periodic intervals as required, the water content of the soil is maintained. This patent does not teach the delivery system that is contemplated herein. The soil conditioning composition is applied to the soil merely as a water solution. The soil must necessarily be subsequently irrigated at periodic intervals to maintain the water content of the soil.
The instant invention is distinguishable over the prior art in that a polymeric solid additive is provided which is formulated to absorb water near the roots, making the water available to plants and lawns as needed, thereby allowing longer time intervals between watering. The instant invention pulses the polymer into the soil using a machine that can withstand the rigors of high pressure pulsing in an economical and reliable fashion.
The remaining citations, which show the state of the art diverge more starkly from the claimed nexus of applicants' invention.